Electrical reactor and method for use thereof and products produced thereby



AND PRODUCTS PRODUCED THEREBY 8 Sheets-Sheet 1 Filed Dec. 7, 1964 h Emmm h E J m 105 GOFU UI QOFM+QE31 a) Sn 2\ a Y mv Nm 6 wm w a nm S on mfiw mw fiw 33 E .W H 5% 4:. m E 1 2 m H P I on 6 g n? 3? v m$ .5 E hl' sl m R L EE m m fia- Z mm l v rm um m mom Q Fm F 5% @m 8 Inventor KURT E.SCHIMKUS J n 7, 1967 K. E. SCHIMKUS 3,328,235

ELECTRICAL AUT AN ETHOD FOR USE THEREOF DUCED THEREBY AN ROD '5 FiledDec. '1", 1964 8 Sheets-Sheet 2 m FIG. 6 20 231 230 g5) 20:

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2 220 2 3 $2: 3 {ll/l 32 //v 222 My 47 us 4A- xv an 202 zm 2m 253 52 56c Inventor KURT E SCHIMKUS Jun 27. 1 6 K. E. SCHIMKUS 3,328,235

ELECTRICAL REACTOR AND METHOD FOR USE THEREOF AND PRODUCTS PRODUCEDTHEREBY Filed Dec- 7. 1964 8 Sheets-$heet a FIG. 7A 1 p. s.i.

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1/ 4244 1,, wi 4M 2 June 27, 1967 AND PRODUCTS PRODUCED THEREBY 8Sheets-Sheet 4 Filed Dec. 3. 1964 m W ll 9 R w 8 6 m .l C F Y m G R H mn O m h m 61 o m w H T m o M W m m H U U 6 M\ R m m 06 m R P 3 L m v. mQ m M u. w I T R 8 E H m 2 m 4 w 1 M m w r W m w M W m u m a w w m 5 o ao m o 5 o wwmwiz Ewmmao 522E wwmwmzgmes 0 0 5: I so x 0 %355 0 0 June27, 1967 E. SCHI us 3,323,235

ELECTRICAL REA R AND ME D USE THEREOF AND PRODUCTS PRODUCED REBY FiledDec. 1'. 1964 8 Sheets-Sheet 5 Inventor By KURT E. SCHIMKUS June 27,1967 K. E. SCHIMKUS 3,328,235

ELECTRICAL REACTOR AND METHOD FOR uss THEREOF AND PRODUCTS PRODUCEDTHEREBY Filed Dec. '9, 1964 8 Sheets-Sheet 6 ram FIG. l5

56\ 544 V 47 so 54 I o I 52 548 563 Invemor B KURT E. SCHIMKUS June 27.1967 K. E. SCHIMKUS 3,328,235

ELECTRICAL REACTOR AN! METHOD FOR USE THEREOF AND PRODUCTS PRODUCEDTHEREBI' Filed Dec. 7, 1964 8 Sheets-Sheet 7 E gm 00 I I 3 CORN sTARcH I300,000 WITHOUT sPARK it] -52 CHEEHAHGE. D I l U I 5200000 K CORN STAREFlG 6 o y WITH sPARK 2 T DISCHARGE. Z WAXY MAlZE STARCH g fl l64 wrrHSPARK DlSCHARGE. D.

O 2 4 6 8 l0 I2 I4 PASSES THROUGH THE REACTOR I00.

CORN sTARcH WITH sPARK DISCHARGE 5 6 b m g CORN sTARcH FIG. Q 2 7WITHOUT SPARK z 2 DISCHARGE 6 g LIJ wm 8 I74 f f '1 m d 9 T WAXY MAIZEsTARcH 4 WITH SPARK DISCHARGE 2 0: CC LL] O 2 4 6 8 I2 I4 0.8 PASSESTHROUGH THE REACTOR I00 CORN sTARcH |82 WITHOUT SPARK FIG '8 DISCHARGE.

3g CORN sTARcH 5 0.4 1 WITH sPARK 4 (I /DISCHARGE q 0 fnvenfor l4 PASSESTHROUGH THE REACTOR By KURT SCHIMKUS United States Patent 3,328,235ELECTRICAL REACTOR AND METHOD FOR USE THEREOF AND PRODUCTS PRODUCEDTHERE- BY Kurt E. Schimkns, Chicago, 111., assignor, by mesneassignments, to Ion Laboratories, Inc., Chicago, Ill., a corporation ofIllinois Filed Dec. 7, 1964, Ser. No. 416,558 54 Claims. (Cl. 162-175)This application is a continuation-in-part of the copending applicationSer. No. 52,136, filed Aug. 26, 1960, now abandoned, which latterapplication is a continuation-in-part of and was co-pending withapplication Ser. No. 761,870, filed Sept. 18, 1958, now abandoned.

The present invention relates to apparatus for and methods of treatingmaterials by means of electrical discharge, and specifically by means ofa spark, and to the products produced thereby.

It is an important object of the present invention to provide animproved apparatus for treating materials comprising a reaction chamberhaving a pair of spacedapart electrodes therein, there being providedstructure for simultaneously passing a stream of liquid and a stream ofgas through the gap between the electrodes, the gas continually purgingthe gap, and structure for causing a spark-type discharge between theelectrodes and through the stream, the spark-type discharge liberatingelectrons and ions and free radicals and generating electromagneticradiation and sound energy directly in the streams for treating materialcarried thereby.

Another object of the invention is to provide an improved apparatus ofthe type set forth wherein the position of the electrodes with respectto each other and within the reaction chamber is adjustable.

Yet another object of the invention is to provide an improved apparatusof the type set forth wherein one of the electrodes is annular and hasat least the inner surface thereof disposed in the reaction chamber andthe other electrode is spaced from the inner surface of the annularelectrode to facilitate control of the paths of the liquid stream andthe air stream between the electrodes.

Still another object of the invention is to provide an improvedapparatus of the type set forth incorporating therein structure servingto confine the liquid stream to a layer on the inner surface of theouter annular electrode and directing the gas stream around the innerelectrode in a manner to assist in maintaining the liquid stream on theinner surface of the outer annular chamber.

Yet another object of the invention is to provide in apparatus of thetype set forth an improved structure of the reaction chamber whichmaterially increases the time that the liquid stream is exposed to theaction of the spark discharge between the electrodes.

Still another object of the invention is to provide in apparatus of thetype set forth tWo inlet passages for liquid, one of the inlet passagesserving to feed the liquid between the electrodes and the other inletpassage serving to feed liquid into the reaction chamber at a point suchthat the latter liquid is not subjected directly to the spark dischargebetween the electrodes.

Yet another object of the invention is to provide a modification of theelectrode structure in apparatus of the type set forth, the electrodesin the modified structure being in axial alignment, and one of theelectrodes being hollow to accommodate the How therethrough of liquidand gas.

Still another object of the invention is to provide in apparatus of thetype set forth an improved power system for supplying energy to generatethe spark discharge, the power source utilizing an applied A.C.frequency in the audio range at a potential of several thousand volts.

Patented June 27, 1967 ICC In connection with the foregoing object,another object of the invention is to provide an improved power sourcefor apparatus of the type set forth wherein the capacitance forming apart of the power source and the gap between the electrodes is resonantin a radio frequency on the order of one megacycle.

Yet another object of the invention is to provide an improved method oftreating materials utilizing the improved apparatus of the type setforth above.

Still another object of the invention is to provide an improved methodof treating starch granules utilizing the apparatus of the type setforth above, the apparatus producing sparks liberating electrons andions and free radicals and generating electromagnetic radiation andsound energy directly in a liquid stream carrying the starch, thesephenomena breaking up the starch granules and causing chain scission ofthe starch and producing chemical groups on the starch that areeffective to reduce ferricyanide solutions.

Yet another object of the invention is to provide an improved method oftreating starch of the type set forth when the starch is presented tothe apparatus in an aqueous slurry containing from about 0.5 to about40% by weight starch at a pH in the range from about 1 to about 9 at atemperature in the range from ambient to about 140 F.

In connection with the foregoing object, another obiect of the inventionis to provide an improved method of treating starch using apparatus ofthe type set forth wherein the starch is present in the spark dischargefor time from about 0.01 second to about 0.3 second and the gas utilizedto sweep the space between the electrodes has the velocity in the rangefrom about 1 to about 5 ft. per second.

Yet another object of the invention is to provide an improved method oftreating starch using apparatus of the type set forth above wherein thestarch slurry has an acid pH, the preferred pH being in the range fromabout 1 to about 6, and the acid being of the type that will react withstarch at a temperature in the range from about 70 F. to F.substantially only to hydrolyze the starch, the preferred acids beinghydrochloric acid and acetic acid.

Still another object of the invention is to provide a method of treatingstarch using the apparatus of the type set forth, the gas stream flowingbetween the electrodes being air and the water stream carrying starchgranules having a buffering agent therein, the preferred bufferingagents when the pH is in the acid range being the amines and theammonium ion, the preferred concentration range of the ammonium ionbeing from about 0.0003 to about 0.3 mole per liter; and the preferredbuffering agents when in the pH is in the basic range being the oxidesof boron, and preferably borate ions.

Yet another object of the invention is to provide an improved method offorming aqueous solutions of hydrogen peroxide utilizing the apparatusdescribed above, the liquid stream preferably being acidified water andthe gas stream being air.

Still another object of the invention is to provide an improved methodof making paper utilizing a starch derivative made in accordance withthe present invention, the starch derivative having an apparentmolecular weight in the range from about 35,000 to about 350,000 andhaving a fcrricyanide reducing value in the range from about 14 to about20.

In connection with the foregoing object, another object of the inventionis to provide an improved method of making paper utilizing a starchderivative produced by the present invention wherein the starch containsat least 5% by weight amylose and the starch is preferably corn starchcontaining at least 20% by weight amylose, the starch derivative havinga molecular weight in the range from about 150,000 to about 320,000 anda ferricyanide reducing value in the range from about 14 to about 17.

Yet another object of the invention is to provide an improved method ofmaking paper wherein a starch derivative made in accordance with thepresent invention and the paper-making fibers are bent together toprovide better association between the starch derivative and the paperfibers in the finished paper product.

Still another object of the invention is to provide an improved methodof making paper wherein a starch slurry is first treated in accordancewith the present invention, the reacted starch slurry is then dilutedand cooked in a range temperature of 180 F. to about 200 F., after whichthe reacted starch slurry is added to the paper stock from which thepaper is formed.

A further object of the invention is to provide a new derivative ofstarch characterized by an apparent molecular weight in the range fromabout 35,000 to about 350,000 and a ferricyanide reducing value in therange from about 14 to about 20.

In connection with the foregoing object, it is another object of theinvention to provide an improved starch derivative containing at leastabout by Weight amylose, the preferred starch product being a derivativeof corn starch containing at least about 20% amylose, and having anapparent molecular weight in the range from about 150,000 to about320,000 and having a ferricyanide reducing value in the range from about14 to about 17.

A still further object of the invention is to provide an improved paperproduct comprising paper-making fibers carrying a sizing of a starchderivative made in accordance with the present invention andcharacterized by an apparent molecular weight in the range from about35,000 to about 350,000 and a ferricyanide reducing value in the rangefrom about 14 to about 20.

In connection with the foregoing object, it is a further object of theinvention to provide an improved paper product of the type set forthwherein the starch sizing includes at least about 5% by weight amylose,and preferably is a corn starch derivative including at least about 20%by weight amylose, and characterized by an apparent molecular in therange from about 150,000 to about 320.000 and a ferricyanide reducingvalue in the range from about 14 to 17.

Further features of the invention pertain to the particular arrangementof the apparatus and of the steps of the methods whereby theabove-outlined and additional operating features thereof are attained.The invention, both as to its organization and method of operation,together with further objects and advantages thereof, will best beunderstoood by reference to the following specification taken inconnection with the accompanying drawings, in which:

FIGURE 1 is a diagrammatic and schematic illustration of an apparatusmade in accordance with the present invention and adapted to carry outthe treating methods of the present invention;

FIG. 2 is an enlarged view in vertical section of the reactor forming apart of the apparatus illustrated in FIG. I of the drawings;

FIGS. 3, 4 and 5 are views in horizontal section through the reactorillustrated in FIG. 2 substantially as seen in the direction of thearrows along the lines 33, 4-4 and 5 5. respectively;

FIG. 6 is a fragmentary view in vertical section illustrating amodification of the reactor illustrated in FIG. 2;

FIGS. 7A through 7E constitute a series of diagrammatic viewsillustrating the time occurrence and intensity of infra-red radiationgenerated in the reactor of FIGS. 1 to 5 upon the application ofdifferent gas pressures to the reactor;

FIG. 8 is a graphical illustration of the relationship between the airpressure applied to the reactor and the energy supplied to the sparkdischarge and the ultraviolet light content of the spark dischargewithin the reactor;

FIG. 9 is a graphical representation of the relationship between theflow rate of a water stream through the reactor and the electricalenergy supplied to the spark discharge, the hydrogen peroxide generatedin the Water and the amount of ultraviolet radiation produced in thespark discharge, respectively;

FIG. 10 is a vertical front view in partial section of a thirdembodiment of a reactor made in accordance with the present invention;

FIG. 11 is a side elevational view of the reactor illustrated in FIG.10;

FIG. 12 is a diagrammatic representation of an apparatus and systemincorporating therein the form of the reactor illustrated in FIG. 10',

FIG. 13 is a side elevational View partly in section of a fourthembodiment of a reactor made in accordance with the present invention;

FIG. 14 is a front elevational view of a fifth embodiment of a reactormade in accordance with the present invention and illustrated asincorporated in an apparatus and system for carrying out the process ofthe present invention;

FIG. 15 is a view in vertical section through the reactor illustrated inFIG. 14;

FIG. 16 is a graphical illustration of the change in the apparent:molecular weight of various starch samples as a result of repeatedpasses through the reactor of FIGS. 1 to 5, the curves respectivelyillustrating the effect on corn starch with no spark discharge in thereactor, the eifect on corn starch with a spark discharge in the reactorand the effect on waxy maize starch with a spark discharge in thereactor;

FIG. 17 is a graphical illustration of the change in ferricyanidereducing value of various starch samples upon repeated passage thereofthrough the reactor of FIGS. 1 to 5, the starch samples beingrespectively corn starch with no spark discharge in the reactor, cornstarch With spark discharge in the reactor, and waxy maize starch withspark discharge in the reactor;

FIG. 18 is a graphical representation of the change in apparent carboxylgroup content of corn starch after repeated passes through the reactorof FIGS. 1 to 5, one of the curves representing the change with sparkdischarge in the reactor and the other curve representing the changewithout spark discharge in the reactor; and

FIG. 19 is a graphical illustration of the inter-relationship betweenthe apparent molecular weight, the ferricyanide reducing value and thenumber of passes through the reactor of FIGS. 1 to 5, data beingpresented for corn starch treated with a spark discharge, corn starchtreated without a spark discharge, waxy maize starch treated with aspark discharge, and corn starch not treated in the reactor buthydrolyzed in aqueous acid solution.

The apparatus 0 FIG. 1

There is illustrated in FIG. 1 of the drawings an apparatus 20 made inaccordance with and embodying the principles of the present invention,the apparatus 20 including a reactor and the electrical, hydraulic andpneumatic components associated therewith. As illustrated in FIG. 1 thereactor 100 includes a reaction chamber 102 surrounding a gap or spacebetween a pair of electrodes and 130, the electrode 120 being hollow andannular in configuration and the electrode being disposed substantiallycentrally therein. An inlet 107 for gas is provided in the upper portionof the reactor 100, an inlet 126 for liquid is provided through theelectrode 120 and an outlet is provided in the bottom of the reactor 100for venting the gas and liquid therefrom into a suitable receptacle suchas the tank 141.

In the operation of the reactor 100, a high potential is applied betweenthe electrodes 120 and 130 to cause the generation of sparkstherebetween. The high operating potential is obtained from power supplywhich is connected to the standard 60 cycle 110 volt A.C. source such asthe conductors 31 and 32, a pair of switches 33 and 34 and associatedfuses 3S and 36 connecting the source to a pair of conductors 37 and 38,respectively, which are in turn connected by fuses 39 and 40 to the mainconductors 41 and 42 within the power of supply for the apparatus 20.

The 110 volt potential applied between the conductors 41 and 42 musthave the potential thereof increased before the application thereof tothe reactor 100 and to this end a suitable transformer system has beenprovided including three variable transformers 70A, 70B and 70Cconnected in parallel and respectively providing an adjustable potentialto the input of three high voltage transformers 80A, 80B and 80C alsoconnected in parallel with each other. In order to connect thetransformers to the conductors 41 and 42, a relay has been providedincluding a coil 51, an armature 52 and three sets of contacts, namely,contacts 53-54, contacts 56 and contacts 57-58. One terminal of therelay coil 51 is connected to the conductor 42 and the other terminalthereof is connected by a conductor 43 to one terminal of a normallyopen start switch 44 and to the contact 56. The other terminal of thestart switch 44 is connected by a conductor 45 through a pump startswitch 46 to the conductor 41, the pump start switch 46 being of thetype which is normally open but remains closed after being moved to theclosed position and remains there until the associated stop switch ismoved to the open position; whereby an energizing circuit for the coil51 is provided when both of the start switches 44 and 46 are closed,which circuit may be traced from the conductor 41 through the closedswitch 46, the conductor 45, the closed switch 44, the conductor 43, andthe relay coil 51 to the other main conductor 42. As soon as the relaycoil 51 is energized, all three sets of contacts are closed; morespecifically, the contact pair 53 54 is closed to connect the conductor41 to a conductor the contact pair 55-56 is closed to establish aholding circuit for the relay coil Si; and the contact pair 5758 isclosed to connect the conductor 42 to a conductor 61. The contact 55 isconnected by a conductor 47 to a normally closed stop switch 48 that isin turn connected by a conductor 48o through a normally closed stopswitch 49 to the conductor 41. After the relay coil 51 has beenenergized, a holding circuit therefor is provided as follows: from theconductor 41 through the normally closed stop switch 49, the conductor48a, the normally closed stop switch 48, the conductor 47, the nowclosed contact pair 5556, and the relay coil 51 to the conductor 42;this holding circuit maintains the relay coil 51 energized to hold thecontacts thereof closed even after the normally open start switch 44 hasmoved from the manually depressed closed position thereof to thenormally open position thereof. A pilot light 51a is provided toindicate when the pump start switch 46 is closed, the light 510 beingconnected between the conductors 42 and 45, and the conductors 42 and 45also are connected as the input to a pump motor 95 which will bedescribed further hereinafter.

After the energization of the relay coil 51 so as to close the contactpairs 5354 and 57-58, direct electrical connection is provided betweenthe conductors 41 and 42 and the respective conductors 60 and 61. Apilot light 59 is connected between the conductors 60 and 61 to providea visual indication that the relay 50 has been operated and thatoperating potential is present on the conductors 60 and 61. Thepotential between the conductors 60 and 61 is also applied to thevariable transformers 70A, 70B and 70C; more specifically, the conductor60 is connected to one terminal of the ammeters 62A, 62B and 62C, theother terminals of the ammeters being connected by conductors 63A, 63Band 63C, respectively, to connections 71A, 71B and 71C on the variabletransformers 70A, 70B and 70C, respectively. The other terminals of thevariable transformers are all connected to the conductor 61. Each of thevariable transformers is provided with a movable contact 73A, 73B and73C, respectively, thereon so that any desired potential ofapproximately 0 volts to approximately 130 volts may be obtained betweenthe movable eontact and the conductor 61. A voltmeter is provided foreach of the variable transformers between the movable contact thereofand the conductor 61, the voltmeters being designated by the numerals64A, 64B and 64C, respectively. Preferably the movable contacts 73A, 73Band 73C are mechanically interconnected so that they can be operatedtogether by a single control diagrammatically represented at 74.

The potentials appearing between the movable contacts of the variabletransformers and the conductor 61 are applied as the inputs to the highvoltage power transformers A, 80B and 80C, respectively. Morespecifically, each of the power transformers has a primary winding thatis connected between the associated movable contact and the conductor61, the primary winding 81A having one terminal thereof connected to theconductor 61 and the other terminal thereof connected by the conductor65A to the movable contact 73A; the primary winding 818 having oneterminal thereof connected to the conductor 61 and the other terminalthereof connected by the conductor 653 to the movable contact 73B; andthe primary winding 81C having one terminal thereof connected to theconductor 61 and the other terminal thereof connected by the conductor65C to the movable contact 73C. Each of the power transformers islikewise provided with a secondary winding 82A, 82B and 82C,respectively, one terminal of each of the secondary windings beingconnected to a con ductor 83 and the other terminal of each of thesecondary windings being connected to a conductor 84. In a specificexample of the power supply 30, the power transformers 80A, 80B and 80Cproduce approximately 12,000 volts in the secondary windings thereofupon the application of 110 volts to the primary windings thereof uponthe application of 110 volts to the primary windings thereof and thecombined current output of the transformers is on the order of 300milliampcres for continuous operation.

The high potential between the conductors 83 and 84, for example thepotential of approximately 12,000 volts, is applied to a bank ofcapacitors 85 connected in parallel relationship with each other,preferably of the capacitors 85 being provided in a typical illustrativeexample of the apparatus 20. Each of the capacitors 85 has a value of500 micr-omicrofarads and is capable of withstanding 35,000 volts D. C.peak voltage thereacross, whereby the capacitor bank has a totalcapacitance of 0.05 microfarad. The conductors 83 and 84 are furtherconnected to a pair of electrodes 86 and 87 which are spacedapart in anair atmosphere and are designed to provide a spark or are therebetweenat a potential well below the breakdown potential of the capacitors 85,for example, at a potential of 20,000 volts so that the electrodes 86and 87 serve as a safety gap for the power system 30. Finally, theconductor 83 is connected to the outer annular electrode and theconductor 84 is connected to the inner electrode to provide theoperating potential for the reactor 100.

In the operation of the reactor 100 it is necessary to provide a streamof gas to sweep the gap between the electrodes 120 and 130 therein, andas is illustrated in FIG. 1, a suitable gas for this purpose in manyreactors is air. There is shown the usual air line 88 to which isconnected in series an air filter 89, a pressure regulator 90, a meter01, the air line 88 communicating with the reactor chamber 102 withinthe reactor 100 through the inlet port 107. The pressure regulator 90 isuseful to adjust and to regulate the pressure in the inlet port 107 at avalue from essentially 0 p.s.i. to about 100 psi.

It will be understood that the material to be treated in the reactor 100may be carried by the air stream entering through the port 107, butusually the material to be treated is carried by a liquid stream thatenters through a port 126 in the electrode 120. A suitable source ofliquid is provided such as the tank 92 into which extends a takeup pipe93, the pipe 93 extending substantially to the bottom of the tank 92.The upper end of the pipe 93 connects to the input of a pump 94, thepump 94 being driven by a pump motor 95 through a drive coupling 96; thepump motor 95 has the electrical input terminals thereof connectedrespectively to the conductors 42 and 45, whereby the motor 95 isoperated upon closure of the switch 46 to cause operation of the pump94. The outlet port of the pump 94 is connected through a flow controlvalve 97 and a flow gauge 98 to a pipe 99 that communicates with theinlet port 126 for the reactor 100. It will be understood that operationof the pump 94 serves to move the liquid within the tank 92 therefromand through the pipe 93, the how control valve 97, the flow gauge 98 andthe pipe 99 into the reactor 100.

The reactor of FIGS.

The details of construction of the reactor 100 are best illustrated inFIGS. 25 of the drawings. Referring to FIG. 2, the reactor 100 includesan upper housing 101, a lower housing 111, an outer annular electrode120 and an inner electrode 130. The upper housing 101 and the lowerhousing 111 are preferably formed of an insulating material, such as asynthetic organic plastic resin, the preferred material of constructionbeing methyl methacrylate resin. The general shape of the reactor 100 iscylindrical and the upper housing 101 more specifically is formedexternally as a cylinder provided with an opening generally centrallythereof contributing to form the reactor chamber 102, an upper innerwall 103 being providecl arranged essentially horizontally andconnecting with a generally conically shaped inner wall 1.04 diverg ingdownwardly therefrom. The upper end of the housing 101 has an opening105 therein receiving therethrough a portion of the inner electrode 130and the lower end of the housing 101 has a threaded recess 106 thereinfor connection to the annular electrode 120. There also is provided inthe housing 101 adjacent to the upper end thereof the inlet port 107which communicates with a coupling 108 mounted on the housing 101 andproviding a fluid-tight connection therewith and also with the air inletpipe 88.

The lower housing 111 is also cylindrical in shape and is provided withan opening centrally thereof to form a part of the reactor chamber 102,an inner wall 113 being provided that is generally conical in shape andconverges downwardly from a larger diameter as at 114 to a relativelysmall outlet opening 115 in the bottom of the housing 111. The upper endof the housing 111 is provided with a threaded recess 116 therein thatthreadedly engages the outer electrode 120 to assemble the housing 111thereto.

As will be explained in greater detail hereinafter, both the gas streamand the air stream introduced into the reactor 100 are directed incircular or spiral paths so that these streams are in essentially aspiral condition as they enter the lower housing 111. In order tominimize interference with the exit of these streams from the lower endof the housing 111, a bafile 117 has been provided in the lower housing111. As may be best seen in FIG. 5 of the drawings, the baffle 117extends across a diameter of the opening in the end of the housing 111and is connected thereto adjacent to the upper end of the battle 117 andadjacent to the lower end thereof. The outer edges of the bnfilc 117 arespaced from the inner wall of the housing 111 throughout the greaterportion of the length thereof as at 118 to provide restricted channelsbetween the edges of the baffle 117 and the inner wall of the housing111.

There also is provided a cross-support 119 connected to the lower end ofthe baffle 117 and disposed in the opening to assist in centering thebattle 117 within the housing 111. Preferably the bafile 117 and thecross-support 119 are also formed of a synthetic organic plastic resinsuch as methyl methacrylate resin. The upper end of the pipe 140 isdisposed in a recess communicating with the open ing 115 in the bottomof the housing 111 and is secured thereto and extends downwardlytherefrom and into the tank 141 (see FIG. 1).

The outer annular electrode 120 and the inner electrode 130 are bothpreferably formed of materials that are good conductors of electricity,a preferred material of construction for both electrodes being aluminummetal. It will be understood that other suitable conducting materialsand particularly conducting metals may be used when the materials beingtreated indicate that this would be desirable.

The electrode 120 is essentially annular in shape having a generallycylindrical outer surface of the same general diameter and shape as thehousings 101 and 111 and a generally cylindrical inner surface forming apart of the wall of the reactor chamber 102. An upwardly extendingthreaded flange is provided on the upper end of the electrode 120 thatthreadedly connects with the threads on the recess 106 of the upperhousing 101; a downwardly extending threaded flange 122 is provided onthe lower end of the electrode 120 that threadedly connects with thethreads on the recess 116 of the lower housing 111; whereby the upperhousing 101, the annular electrode 120 and the lower housing 111 can bethreadedly interconnected to provide the reactor 100 containing anddefining the reactor chamber 102 therein. The inner surface of theannular electrode 120 is provided with a helical groove 123 thereinwhich spirals downwardly from the upper end thereof to the lower endthereof and tends to direct a liquid stream or the gas stream impingingthereon in a downwardly spiraling path. Formed in the electrode 120 is apassage 124 communicating at one end with the exterior thereof andspecifically with a coupling 125 that connects to the pipe 99 and at theother end communicates with an inlet port 126 on the inner surface ofthe annular electrode 120, see FIG. 4. There further is provided in theelectrode 120 a threaded opening on the exterior thereof that receives ascrew 127 that connects the adjacent end of the conductor 83 to theelectrode 120 to apply operating potential thereto.

The inner electrode 130 includes an upwardly extending stem or rod 131that is generally circular in cross section and extends upwardly throughthe opening 105 in the upper end of the upper housing 101 and inoperation is connected to the conductor 84 for the application ofoperating potential thereto. The lower end of the rod 131 carries anenlarged head 132 which is formed with an upwardly and inwardly slopingconical surface 133. a downwardly and inwardly sloping conical surface134 and a cylindrical surface 135 joining the surfaces 133 and 134.Substantially all portions of the surface 135 are equidistantly spacedfrom the adjacent inner surface of the annular electrode 120 to providetherebetween a gap across which a spark discharge is produced upon theapplication of operating potential between the electrodes 120 and 130,as will be explained more fully hereinafter.

Referring now specifically to FIGS. 3 and 4 of the drawings, the mannerin which a downwardly spiraling action is applied to both the gas streamand the liquid stream within the reactor 100 will be described indetail. Referring first to the gas stream, it will be seen from FIG. 3of the drawings that the inlet port 107 is directed tangentially withrespect to the inner annular wall 104 of the upper housing 10], wherebgas entering through the port 107 is impinged upon the annular wall 104and is forced into a circular or spiraling path. The direction ofspiraling of the gas stream imparted thereto by the configuration ofFIG. 3 is in a like direction and like sense as the groove 123 on theinner surface of the annular electrode 120. The liquid stream inlet 124and the port 126 therefore are also disposed tangentially with respectto the inner surface of the annular electrode 120, see FIG. 4, wherebyto impart to a liquid stream entering therethrough a spiraling motion,the direction and sense of the spiraling motion imparted to the liquidstream being the same as the direction and sense of the groove 123 onthe inner surface of the annular electrode 120. The like downwardspiraling motion of the gas stream also reinforces the motion of theliquid stream and together with centrifugal force serves to hold theliquid stream in a spiraling, annular and gradually falling path alongthe groove 123 of the annular electrode 120 so that the liquid streamtravels a path having a substantial length in moving from the inlet port126 to the lower end of the annular electrode 120, it being pointed outthat the liquid stream is in the gap between the electrodes 120 and 130so long as it is in position in the groove on the electrode 120.

In an illustrative example of the reactor 100, the overall length of thereactor is 6.5" and the diameter thereof is 2.4"; the diameter of thereaction chamber 102 at the upper end thereof is 1.1" and the maximuminternal diameter thereof is 1.65; the longitudinal extent of thehelical groove 123 is 0.625, the pitch of the groove 123 is 6 /2 turnsper inch, and the internal diameter of the electrode 120 isapproximately 1.655"; the diameter of the air inlet port 107 is 0.085"and the diameter of the liquid inlet port 126 is 0.098"; the maximumdiameter of the inner electrode head 132 is 0.825, whereby the minimumspark gap between the electrodes 120 and 130 is 0.415"; the head 132 isfurther positioned approximately midway between the inlet port 126 andthe lower edge of the annular electrode 120 so as to provide a maximumexposure of the liquid stream to the spark.

The reactor of FIG. 6

There is illustrated in FIG. 6 of the drawings a modification of thereactor 100 described above with respect to FIGS. 2-5 of the drawings;where appropriate, like numerals in the 200 series have been applied toparts of the reactor 200 to correspond to like parts of the reactor 100described above.

The reactor 200 includes an upper housing 201, a lower housing 211, anouter annular electrode 220 and an inner electrode 230. The upperhousing 201 is formed identical with the housing 101 described above andas illustrated includes an inner annular wall 204 defining a portion ofthe reactor chamber 202 and a threaded recess 206 at the lower endthereof for connecting the electrode 220. The lower housing 211 is ofmodified construction and is formed with an internal cylindrical wall213 that is formed as a continuation of the inner wall of the annularelcctrode 220. The lower end of the housing 211 is provided with athreaded recess 215 for connection to an outlet battle to be describedhereinafter. There further is provided in the upper portion of thehousing 211 a second liquid stream inlet 244 communicating at one endwith a coupling 245 mounted on the housing 211 and connecting to asecond liquid inlet pipe 247; the other end of the inlet passage 244communicates with a second inlet port 246 in the wall of the housing 211and disposed below the annular electrode 220 for the introduction for asecond or additional stream of liquid or gas if desired.

The lower end of the housing 211 is closed by a baflle 250, the baffle250 having an outer annular wall threaded as at 251 and threadedlyengaging the threaded recess 215 to mount the bafile 250 on the lowerend of the housing 211. The upper portion of the battle 250 extends intothe housing 211 and terminates in an upwardly disposed conical surface252 that merges with a vertical annular wall 253 spaced from the innerannular wall 213 of the housing 211. The lower end of the baffle 250carries a downwardly directed annular projection 254 which is providedinwardly thereof with an upwardly extending vertical passage 255extending upwardly toward but spaced from the conical surface 252. Aplurality of horizontally disposed and axially arranged passages 256 areprovided communicating between the outer annular wall 253 and thevertical passage 255, four of the horizontal passages 256 beingprovided, for example.

The annular electrode 220 is formed substantially identical with theannular electrode 120 described above and more specifically includes anupwardly directed threaded flange 221 threadedly engaging the lower endof the upper housing 201 as at 206, and a downwardly extending threadedflange 222 threadedly engaging the threaded recess 216 on the upper endof the lower housing 211. The inner surface 223 of the electrode 220 isformed smooth and as a cylinder having a diameter substantially equal tothe diameter of the surface 213 on the lower housing 211. A first liquidstream inlet passage 224 is provided communicating at the other end withthe coupling 225 connected to the pipe 99 and communicating at that endwith an inlet port 226 disposed above the head 232 on the innerelectrode 230.

The inner electrode 230 is formed identical to the inner electrode 130described above, and more specifically, includes an upward extending rod231 carrying at the lower end thereof a head 232 having an upper conicalsurface 233, a. lower conical surface 234 and an annular surface 235joining and interconnecting the conical surfaces 233 and 234. Theannular surface 235 of the inner electrode 230 is spaced from the innersurface 223 of the outer electrode 220 completely therearound to providea uniform spark gap therebetween.

The reactor 200 can be readily inserted in the apparatus 20 of FIG. 1for the reactor illustrated therein. The annular electrode 220 isconnected to the conductor 83, the inner electrode 230 is connected tothe conductor 84, the first inlet coupling 225 is connected to the pipe99 and the second inlet coupling 245 is connected to the pipe 247 whichis in turn connected to a liquid supply system like that supplying thepipe 99. The materials of construction and the relative sizes of allparts of the reactor 200 are the same as for the like parts of thereactor 100 described above.

Operation of the apparatus 20 In the operation of the apparatus 20, theparts are first connected as illustrated in FIG. 1 of the drawings. Asuitable supply of desired liquid is placed in the tank 92 and a sourceof air under pressure is connected to the pipe 83. The power supply 30is then energized by closing the switch contacts 33 and 34 so as tosupply line potential of approximately volts ac. through the fuses 3Sand 36, the conductors 37 and 38, and the fuses 39 and 40 to the mainconductors 41 and 42. The pump start switch 46 is then closed to providea connection from the conductor 41 through the switch 46 to theconductor 45 connected to one terminal of the pump drive motor 95, andfrom the other terminal of the pump drive motor 95 to the main conductor42; simultaneously, energization potential is applied to the signallight 51A to indicate that the pump 95 is operating. The pump motor 95acting through the coupling 96 drives the pump 94 to draw liquid fromthe tank 92 through the pipe 93 into the inlet port of the pump 94 andout of the outlet port of the pump 94 and through the valve 97, themeter 98 and the pipe 99 to the inlet port 126 of the reactor 100. Theoperation of the pump 94 and the setting of the valve 97 are adjusted toproduce the desired fiow rate of liquid into the reactor 100 a typicaloperating flow rate of the liquid at the port 126 as indicated by theflow meter 98 is in the range from about 0.05 gallon per minute to about1.5 gallons per minute, a typical operating value being 0.6 gallon perminute. The force of the liquid striking the inner surface of theelectrode and particularly the helical groove 123 therein forces theliquid into a swirling motion and substantially confines it to a thinfilm upon the electrode 120, the residence time of the liquid in thespark gap between the electrodes 120 and 130 being for examples 0.8second at a flow rate of 0.05 gallon per minute and 0.027 second at aflow rate of 1.5 gallons per minute, a typical operating value being0.069 second at a flow rate of 0.6 gallon per minute. The tangentialentry of the port 126 with respect to the helical groove 123 materiallyassists in imparting a swirling motion to the liquid stream as it fallsdownwardly through the spark gap between the electrodes 120 and 130along the helical groove 123.

The gas supplied through the pipe 88 and into the reactor 100 alsoassists in holding the liquid stream in the desired configuration uponthe inner surface of the anular electrode 120. The air pressure asmeasured by the gauge 91 and as controlled by the pressure regulator 90may be in the range from about psi. to about 80 psi. or higher, atypical operating value being p.s.i. when the gas being used is air; theair flow at 5 p.s.i. is approximately 1.8 cu. ft. per minute whichresults in each quantity of air passing through the spark gap betweenthe electrodes 120 and 130 in a time period of approximately 0.047second; at the operating pressure of 10 p.s.i., the air flow rate isapproximately 1.5 cu. ft. per minute and the time required for the airto pass through the spark gap is approximately 0.036 second; and at anair pressure of p.s.i., the flow rate of air is about 3.75 cu. ft. perminute and requires about 0.023 second for the air to pass through thespark gap. The gas velocity through the reactor 100 is in the range fromabout 1 foot per second to about 5 feet per second. The air flowingaround the inner eiectrode 130 and against the inwardly disposed surfaceof the liquid stream serves to assist in holding the liquid stream inthe desired position and against the inner surfaces of the annularelectrode 120 and particularly in the helical groove 123 thereof. Thegas entering the reactor 100 through the port 107 also serves to sweepparticles from the spark gap between the electrodes 120 and 130 as willbe described more fully hereinafter.

With the gas stream flowing through the reactor 100 and specificallythrough the spark gap between the electrodes 120 and 130, the reactorstart switch 44 may now be closed. Closure of the reactor start switch44 completes a circuit from the conductor 41 through the pump startswitch 46, the conductor 45, the reactor start switch 44, and theconductor 43 to one terminal of the relay coil 51; and from the otherterminal of the relay coil 50 to the main conductor 42, whereby toenergize the coil 51 and to move the armature 52 thereof to close theassociated pairs of relay contacts 53-54, 55-56 and 57-58. Closure ofthe relay contacts 55-56 creates a holding circuit for the relay coil51, it being pointed out that although the pump start switch 46 is ofthe type that remains closed after having been moved to that position,the reactor start switch 44 is of the momentary contact type and will beimmediately moved to the open position upon release of the closurepressure therefrom. The holding circuit for the relay coil 51 can betraced from the main conductor 41 through the normally closed pump stopswitch 49, the conductor 480, the normally closed reactor stop switch48, the conductor 47, the now closed relay contacts 55-56, the conductor43, the relay coil 51 and to the other main conductor 42. In passing itis noted that the start reactor switch 44 is ineffective to actuate therelay 50 if the pump start swich 46 is not closed, whereby to insurethat a liquid stream is present in the reactor 100 before closure of therelay contacts 53-54 and 57-58 for a purpose which will be explainedhereinafter.

Energization of the relay coil 51 causes closure of the relay contacts53-54 that provide a connection between the main conductor 41 and theconductor 60; and actuation of the relay 50 likewise closes relaycontacts 57-58 that serve to connect the main conductor 42 to theconductor 61. Connection of the conductors 41 and 42 to the conductors60 and 61, respectively, applies 110 volt A.C. operating potentialbetween the conductors 60 and 61; the signal light 59 is immediatelyenergized to indicate that the relay is in the operating ositionthereof.

Application of the operating potential to the conductors 60 and 61immediately applies that potential to the variable transformers A, 70Band 70C. The operating potential is applied to the variable transformer70A, for example, from the conductor 60 through the ammctor 62A and theconductor 63A to one of the input terminals thereof and from theconductor 61 directly to the other input terminal thereof. The potentialderived from the variable transformers 70A, 70B and 70C and applied asthe input to the step-up transformers A, 80B and 80C, respectively,depends upon the setting of the contacts 73A, 73B and 73C, the inputpotential to the step-up transformers being that between the conductor6-1 and the conductors 65A, 65B and 65C, that potential being adjustableby means of the linkage 74 interconnecting the sliding contacts 73A, 73Band 73C, respectively; the value of the operating potential applied asan input to the stepup transformers is indicated by the meters 64A, 64Band 64C connected across the primary windings 81A, 81B and 81C,respectively. In a typical operating example, the stepup transformersare of a type and the adjustment of the control 74 is such that 12,000volts A.C. are developed as outputs from the secondary windings 82A, 82Band 82C of the step-up transformers, which potential is applied throughthe conductors 83 and 84 to the bank of capacitors 85 and serves tocharge the capacitors 85 toward the peak voltage, which is, for example,approximately 17,000 volts when the output from the secondary windingsof the step-up transformers is 12,000 volts R.M.S. The potential on thecapacitors 85 is applied by the conductors 83 and 84 to the electrodes120 and 130, respectively, of the reactor 100.

The operation of the power supply 30 can be interrupted by openingeither the normally closed reactor stop switch 48 or the normally closedpump stop switch 49, these switches being in series in the holdingcircuit for the relay coil 51. Opening either of these switchesdeenergizes the coil 51 and causes the movable relay contacts 53, 55 and57 to move to the open positions thereof, thus removing operatingpotentials from the variable transformers 70A, 70B and 70C, andconsequently interrupting the power for the spark discharge in thereactor 100. If only the reactor stop switch 48 is opened, the pumpmotor will continue to operate; on the other hand, if the pump stopswitch 49 is opened, then the pump start switch 46 is likewise openedand operation of the pump motor 95 is stopped.

The discharge between the electrodes and during the operation of anapparatus 20 is believed to be fundamentally a spark discharge, asdistinguished from a glow or an arc discharge. In fact the sparkdischarge can be considered to be a transitional breakdown which occursin transition from a glow discharge to an arc discharge. The conditionsunder which a spark discharge is obtained, and specifically thebreakdown or sparking potential depends upon many factors including thepressure within the reaction chamber 102 and the separation or distancebetween the electrodes 120 and 130 and specifically is a function of theproduct of the pressure and the electrode seperation. In order toencourage the formation of the more desirable spark discharge, it ispreferred to operate the reaction chamber 102 at approximatelyatmospheric pressure, and even at an air pressure of 20 psi. asindicated by the gauge 91, the actual pressure as determined by apressure probe in the spark gap being on the order of 3" of water aboveatmospheric. Either an increased pressure or a decreased pressure tendsto discourage and prevent a sparktype discharge between the electrodes120 and 130.

In a spark discharge, the entire path between the electrodes 120 and 130is ionized and a characteristic light is emitted from the path of thespark discharge. The light is in turn caused by the photon emissionresulting from the recombination and the decay from excited states tomore stable states of orbital electrons in atoms along the spark path.The spark is propagated at a rapid rate across the gap and is propagatedat a rate much faster than electrons can traverse the spark gap. It isbelieved that initially an electron is emitted from the electrode thatis acting as a cathode, and this initial electron will produce a heavyavalanche of cumulative ionization along the spark path. The lightresulting from the decay processes referred to above will also produceionization throughout the gas present between the electrodes, and thelight will also produce electrons at electrode surfaces by thephotoelectric effect. The resultant electrons from these phenomena willin turn produce further avalanches through the entire spark gap, so thatin a time on the order of second the entire path between the electrodes120 and 130 becomes conducting. At the approximately atmosphericpressure prevailing through out the spark gap within the reactor 100,the spark will be confined to a relatively narrow region, so that theconducting path while not straight will be a well-defined line.

It will be seen that there will be formed in the spark gap a substantialquantity of electrons and ions, which electrons and ions will be presentin both the gas stream and the liquid stream and therefore will be inintimate contact and association with any reactants carried thereby,whereby to provide maximum opportunity for chemical and physicalreactions occurring therefrom. If certain types of molecules arepresent, such for example as water, free radicals are also readilyformed and are available for reaction with reactants present in thespark gap, the free radical being intimately mixed throughout the sparkgap and therefore intimately mixed with the reactants therein.

The photons produced in the spark also provide a substantial source ofelectromagnetic radiation which varies in wavelength from the infra-redregion through the visible region to the ultra-violet region of thespectrum. Substantial quantities of electromagnetic radiation areproduced as determined by measurement with meters as will be describedmore fully hereinafter. The electromagnetic radiation is presentdirectly in the spark gap and therefore is brought into intimate contactwith any reactants present within the spark gap, whereby maximumutilization can be made thereof in carrying out the reactions Within thereactor 100.

The rapid heating and cooling of quantities of gas within the reactor100 also produces a substantial amount of sound energy that is presentdirectly in the gas and liquid streams and also imparts energy to thereactants present therein. In this connection it also is pointed outthat the swirling motion of both the gas stream and the liquid streamresults in a high shear action upon materials carried thereby within thereactor 100. As a result of these phenomena, operation of the reactor100 is characterized by a high shrill piercing sound that demonstratesthe high amount of energy available from these sources within thereactor 100.

It is also found that a more desirable form of discharge is obtainedwhen the operating potential is in the range from about 4,500 volts toabout 20,000 volts or higher between the electrodes 120 and 130. Thepreferred operating potential when using the reactor 100 having thedimensions described above is 9,000 volts, which value is readilyattained by producing a 12,000 volt output from the secondary windingsof the step-up transformers 80A. 80B and 80C. A more desirable form ofspark discharge is also obtained if the capacitance represented by thecapacitance represented by the capacitors 85 and the reactance of theremainder of the power source 30 and the spark gap between theelectrodes 120 and 130 is resonant at a radio frequency, the preferredvalue being approximately 1 megacycle. It will be understood that thesystem has a low Q, whereby there is substantial radiation atfrequencies above and below 1 mcgacycle, but there is a definite maximumradiation at approximately 1 megacycle as determined by measurementusing an absorption meter. It can be demonstrated mathematically thatwith the above conditions, very high concentrations of power areproduced in the spark, these concentrations of power being on the orderof 1 to 10 megawatts, whereby substantial amounts of power and energyare available at points within the reaction chamber 102 to elToctreactions between the materials carried by the gas stream and the liquidstream therein.

A most important factor in obtaining a desirable spark discharge withinthe reactor is the pressure of the gas stream entering through the inletport 107. The gas stream serves to sweep the area between the electrodesI20 and and is believed therefor to discourage arc discharge and toencourage spark discharge by quickly extinguishing any incipient arcdischarges that may occur in the spark gap. Referring to FIGS. 7A to 7Eof the drawings, there are illustrated replicas of actual experimentaldata which indicate that both the frequency of spark discharge and theintensity of spark discharge is increased with an increase in the inletgas pressure at the inlet port 107. The data in FIGS. 7A to 7E wereobtained by using distilled water as a liquid stream at a flow rate of0.5 gallon per minute through the reactor 100, and utilizing air as thegas stream at various pressures as indicated by the pressure gauge 91 inFIG. 1. The frequency and intensity of spark discharge was determined bymeasuring the infra-red energy generated by the spark discharge, aninfra-red sensitive photometer being utilized in combination with aninfra-red filter to detect the infrared energy and to convert thatenergy into a corresponding electrical signal that was displayed uponthe face of an oscilloscope. In FIGS. 7A to 7E there are shownreproductions of actual oscilloscope tracings having a horizontal extentequal to three cycles of the applied potential on the conductors 83 and84, the frequency of the spark discharge being determined by theoccurrence of the vertical peaks and the intensity of the sparkdischarge being indicated by the length of the vertical peaks.

There is shown in the graph of FIG. 7A the frequency and intensity ofspark discharge obtained when the air inlet pressure as indicated by thegauge 91 was 1 p.s.i. It will be noted that there were approximatelyfour spark discharges per cycle of the applied operating potential andwith an intensity on the order of 1 to 2 of the arbitrary unitsillustrated. The graph in FIG. 7B represents the spark dischargeobtained when the air pressure is indicated by the gauge 91 is increasedto 10 p.s.i. It will be noted that there is a general increase in boththe frequency and in the intensity of the spark discharge. The graph inFIG. 7C represents the discharge when the air pressure as indicated bythe gauge 91 is 30 p.s.i. and indicates yet further increase in thefrequency and the intensity of the spark discharge. In the graph of FIG.7D there is illustrated the spark discharge obtained when the airpressure is indicated by the gauge 91 is 50 p.s.i. and a yet furtherincrease in the frequency and intensity of the discharge is noted.Finally in the graph of FIG. 7E there is illustrated the spark dischargeobtained when the air pressure as indicated by the gauge 91 was 80p.s.i. and showing yet a further increase in both the frequency andintensity of spark discharge in the spark gap between the electrodes 120and 130.

As has been pointed out above, ultra-violet radiation is also producedby the spark discharge. By means of an ultra-violet meter the change inultra-violet radiation production by the spark discharge was measured atvarious air pressures as indicated by the gauge 91. The results areplotted in FIG. 8 on the curve the vertical axis indicating the DC.microamperes measured by the ultraviolet meter and the horizontal axisindicating the air pressure in psi. as measured by the gauge 91. It willbe noted that the ultra-violet increased from a value of 10 microamperesat an inlet air pressure of psi. to a value of 18 microamperes at an airpressure of 60 p.s.i., in dicating that more spark discharge wasobtained as the inlet air pressure is increased, thus confirming thedata presented in FIGS. 7A to 713 described above. There also is plottedin FIG. 8 a curve 185 of the total primary current in amperes asindicated by the meters 62A, 62B and 62C versus the inlet air pressure.It will be noted that the primary current increased from a value of 27amperes at an inlet air pressure of 5 psi. to a value of 34 amperes atan inlet air pressure of 60 p.s.i. indicating that more energy was beingtransferred from the power source 30 to the reactor 100 as the inlet airpressure increased, and therefore also confirming the data presented inFIGS. 7A to 7E as well as confirming the data presented in the curve180.

The fiow rate of the liquid stream also affects the type of sparkdischarge obtained, the frequency and intensity of the spark dischargegenerally decreasing with an increased liquid stream flow. There isplotted in FIG. 9 of the drawings curves representing the effect ofdifferent water flow rates as indicated by the flow meter 98 in FIG. 1(plotted along the horizontal axis) upon the ultra-violet radiationproduced in the water stream expressed in grants per liter and theamount of current indicated by the meters 62A, 62B and 62C expressed inamperes (the latter variables being plotted on the vertical axis).

Referring to FIG. 9, the curve 190 is a plot of the amount ofultra-violet radiation produced from the spark gap as indicated by theultra-violet meter and expressed in DC microamperes with varying flowrates of water as measured by the flow meter 98 in cc. per minute. Itwill be noted that the ultra-violet generated varies from a value of 20microamperes at a flow rate of 270 cc. per minute to a value of 10microamperes at a flow rate of 1,700 cc. per minute, i.e., theultra-violet radiation produced in the spark gap within the reactor 100generally decreases as the rate of flow of water through the reactorincreases.

As has been mentioned above, the passage of the spark through air anddistilled water in the reactor 100 is believed to produce free radicals,and in any event, hydrogen peroxide is produced therein. As is indicatedby the curve 193 in FIG. 9, at a water flow rate of 270 cc. per minute,0.027 grams of hydrogen peroxide are generated per liter of water flowthrough the reactor 100. The amount of hydrogen peroxide produceddecreases to a value of approximately 0.016 grams per liter at a flowrate of 1800 cc. per minute; whereby it will be seen that the amount ofhydrogen peroxide produced decreases with an increase in the flow rateof the water through the reactor 100 and decreases in a manner generallycorresponding to the decrease in the ultra-violet radiation.

The decrease in energy consumed in the reactor 100 with the increasedflow rate of water thereto is confirmed by measuring the current in thepower supply 30 as indicated by the meters 62A, 62B and 62C. The graph196 in FIG. 9 is a plot of the current indicated by those meters versusthe flow rate, whereby it will be seen that a flow rate of 270 cc. perminute, the total current drawn is 37 amperes, and as the water flowrate increases the current drawn decreases so that at a flow rate of1700 cc. per minute the current drawn is only 23 amperes. This confirmsthe data indicated by the curves 190 and 193 dis cussed above, namely,that there is less energy transferred to the reactants within thereactor 100 as the rate of fiow of water through the reactor 100increases.

Recapitulating, the apparatus 20 illustrated in FIG. 1 upon theestablishment of the liquid stream and the gas stream threthrough andafter closure of the switches 44 and 46 to provide operating potentialbetween the electrodes and 130, is operative to produce essentially aspark discharge through and in the liquid stream and the gas streamwithin the reactor 100. The spark discharge liberates electrons and ionsand in the presence of certain compounds also generates free radicalsdirectly in the gas stream and the liquid stream so as to permit directreaction with any reactants carried thereby. There also is generatedelectromagnetic radiation, sound energy and shear forces directly in thestreams and for causing other physical and chemical actions upon anyreactants carried thereby. In general, a more frequent and moreintensive spark discharge is obtained with increasing gas stream flowrates, the gas stream serving to sweep the gap between the electrodes120 and so as to continually renew the optimum conditions for theproduction of spark discharge therebetween. Conversely, increasing theliquid flow rate tends to decrease the spark discharge between theelectrodes 120 and 130. It further is pointed out that largeconcentrations of energy can be present in the gas stream and liquidstream and imparted thereby by spark discharge, these concentrations ofenergy being on the order of 1 to 10 megawatts when the capacitors 85,the reactance of the power supply 30 and of the spark gap in the reactor100 are adjusted to have a peak discharge of the capacitors atapproximately a 1 megacycle rate. These high concentrations of energy,although having a very brief time duration, make possible unusual anddesirable chemical and physical reactions within the reaction chamber102.

The reactor 0 FIGS. 10 to 12 Referring to FIGS. 10 to 12 of thedrawings, there is illustrated a third embodiment of the inventionemploying a reactor generally designated by the numeral 300. The reactor300 comprises a generally rectangularly shaped block 301 that is formedof an electrical insulating material such as plastic, glass, ceramic orthe like, and is preferably formed of a transparent or translucentsynthetic organic plastic resin, preferably methyl methacrylate resin.The block 301 is provided with a centrally located reaction chamber 303defining a reaction zone into which extend a pair of electrodesgenerally designated by the numerals 304 and 305. The electrodes arepreferably formed of metal, the preferred metal being aluminum. Theelectrodes are provided with inner ends 304a and 305a, respectively,that are disposed Within the reaction chamber 303 and are spaced fromeach other a distance to insure a proper spark discharge therebetweenwhen a suitable potential is applied between the outer ends thereofgenerally designated by the numerals 304b and 30511. The electrodes 304and 305 are held in the proper adjusted position by means of two screws306 and 307, respectively, which are threaded into the block 301,adjustment of the spacing of the inner ends 304a and 305a of theelectrodes being possible by loosening of the screws 306 and 307 andsubsequent tightening thereof after adjustment of the positions of theelectrodes.

A number of passageways are provided through the block 301 allcommunicating with the reaction zone 303 for use in introducing liquidstreams and gas streams thereinto. A first insulated pipe 308 isprovided mounted in the body 301. having an opening therethroughcommunicating with the reaction chamber 303 through a restricted passage312. The flow of material through the pipe 308 and into the reactionchamber 303 may be regulated by means of a needle valve 313 threadedlymounted in the body 301 and positioned to be moved into and out ofblocking relationship with respect to the passage 312 so as to regulatethe flow of material through the pipe 308 and into the reaction chamber303. A second insulated pipe 310 is provided mounted on the block 301and having an opening therethrough communicating with the reactionchamber 303 and through a restricted passageway 314. A needle valve 315is provided to control the flow of material from the pipe 310 throughthe passage 314 and into the reaction chamber 303, the needle valve 315having the exterior surface thereof threaded and in threaded associationwith the associated opening 301. It will be seen that the needle valves313 and 315 can be threadedly moved with respect to the block 301 andwith respect to the associated restricted passages 312 and 314,respectively, so as to control the flow of materials between thereaction chamber 303 and the insulated pipes 308 and 310, respectively.A third insulated pipe 309 is mounted on the block 301 and has anopening therein communicating with the reaction chamber 303; and afourth insulated pipe 311 is mounted upon the block 301 and has anopening therethrough communicating with the reaction chamber 303.

The reactor 300 can be connected in the system illustrated in FIG. 1 ofthe drawings by making the suitable electrical, gas and liquidconnections thereto. There is illustrated in FIG. 12 of the drawings asimplified and schematic illustration of another system incorporatingtherein the reactor 300 of FIGS. 10 and 11. The electrodes 304 and 305are connected at their outer ends to conductors 316 and 317,respectively, which are also connected to the terminals of the secondarywinding 318 of a power step-up transformer 319. The transformer 319 hasa primary winding 320 which may be connected to any suitable source ofoperating potential such as a 110 volt 60 cycle A.C. source. A capacitor323 is also connected between the conductors 316 and 317, the capacitor323 being illustrated as of the variable type. If desired, the point onthe secondary winding 318 of the transformer 319 may be grounded asillustrated.

The inlet pipe 308 is connected by a conduit 324 to the outlet 325 of apump 326 which has an inlet 327 connected to a suitable source of gas,such as the atmosphere. Operation of the pump 326 draws air from theatmosphere and compresses it and forces it under pressure through theconduit 324 and the pipe 308 into the reaction chamber 303 of thereactor 301. The pipe 310 is connected to one end of a conduit 328having the other end thereof connected to the outlet 329 of a pump 330which in turn has an inlet 331 communicating with the contents of a tank332 containing a liquid to be pumped into the reaction zone 303 of thereactor 300. The pipe 309 is connected to one end of a conduit 333having the other end thereof connected to the outlet of an elevated tank334 containing a liquid, a control valve 335 being provided in theconduit 333 to control the flow of the liquid from the tank 334 throughthe conduit 333 and the pipe 309 and into the reaction chamber 303. Thepipe 311 is connected to an outlet conduit 336 which empties into a tank337 for receiving the material fed through the reaction zone 303 of thereactor 300.

In the operation of the system illustrated in FIG. 12 of the drawingsand incorporating therein the reactor 300, the pump 326 is actuated tocause a flow of pressurized air through the inlet pipe 308; the valve335 is opened to permit flow of liquid from the tank 334 through theconduit 333 and the inlet pipe 309 into the reaction chamber 303. Havingestablished the air stream and the liquid stream through the reactor300, the operating potential can be applied to the transformer 319,specifically, to the terminals 321 and 322 thereof whereby to cause ahigh potential on the order of several thousand volts to be producedbetween the output terminals of the secondary winding 318 and betweenthe conductors 316 and 317. With the position of the electrodes 304 and30 adjusted with the proper potential applied therebetween from theconductors 3'16 and 317, respectively, and with the suitable air andliquid streams flowing through the reactor 300, a high voltage sparkdischarge is obtained between the electrodes 304 and 305 and within thereaction chamber 303 to impart energy to the materials carried by thevarious streams. The discharge is of the same general character andproduces the same physical and chemical results discussed above indescribing the apparatus 20 of FIG. 1. The treated liquid and gasstreams flow from the reactor chamber 303, through the pipe 311 and theconduit 336 and are collected in the tank 337. A second liquid or asecond gas can be fed through the pipe 310 by operation of the pump 330to be mixed in the reaction chamber 303 with the liquid and gas streamsdescribed above. It further is pointed out that either gas or liquid canbe introduced through any one of the pipes 308, 309, 310 and 311, itsimply being required that at least one of the pipes be available as adischarge, so that three ditferent streams may be fed to the reactor 300at any given time.

It is noted that the electrodes 304 and 305 are in axial alignment withone another, the inlet pipes 308 and 310 are in general axial alignmentwith each other, the inlet pipes 309 and 311 are in axial alignment witheach other and all are converging toward the reaction chamber 303.

The reactor 0 FIG. 13

There is illustrated in FIG. 13 of the drawings a fourth embodiment of areactor 400 made in accordance with and embodying therein the principlesof the present invention. The reactor 400 includes a block 438 ofsuitable insulating material, preferably a synthetic organic plasticresin, the preferred resin being methyl methacrylate resin. Formedgenerally centrally of the block 438 is a reaction chamber 403 havingpassages 412 and 414 extending outwardly therefrom and toward theadjacent edges of the block 438. A first pipe 408 formed of insulatingmaterial is mounted on the block 438 and has an opening therethroughcommunicating through the passage 412 with the reaction chamber 403. Asecond pipe 410 formed of electrical insulating material is also mountedupon the block 438 and has an opening therethrough communicating throughthe passage 414 with the reaction chamber 403. A third pipe 409 formedof an electrical conducting material is mounted in the block 438 and hasan opening therethrough communicating directly with the reaction chamber403, the pipe 409 being connected to a conductor 416, whereby the pipe409 serves as one of the electrodes for the reactor 400. A secondelectrode 460 is mounted in the block 438, the electrode 460 having anexternal surface thereof threaded and threadedly engaging a threadedopening in the lower portion of the block 438. The upper end 406a of theelectrode 460 extends upwardly into the reaction chamber 403 and thespacing thereof from the lower end of the electrode 409 can be adjustedby threading the electrode 460 inwardly and outwardly with respect tothe block 438. The lower end of the electrode 460 is connected to aconductor 417, it being understood that a suitable operating potentialis applied between the conductors 416 and 417 during the operation ofthe reactor 400.

In the operation of the reactor 400, the pipe 408 receives either a gasor liquid therethrough for introduction into the reaction chamber 403;the pipe 409 receives therethrough a gas or liquid stream that impingesupon the gas or liquid stream from the pipe 408 within the reactionchamber 403. The streams within the reaction chamber 403 are exposed tothe spark discharge established between the electrodes 409 and 460, in amanner similar to that described in detail above with respect to theapparatus 20 of FIG. 1. The reacted streams flow from the reactionchamber 403 through the pipe 410 and thus out of the reactor 400.

The reactor 0 FIGS. 14 and 15 Referring to FIGS. 14 and 15 there isillustrated an apparatus incorporating therein a fifth form of a reactor500 made in accordance with and embodying the principles of the presentinvention. The reactor 500 includes a generally cylindrical body 540formed of an electrical insulating material such as plastic, glass,ceramic, or

the like, and is preferably translucent or transparent, the preferredmaterial of construction being a synthetic organic plastic resin, thepreferred resin being methyl methacrylate resin. Formed centrally in theupper portion of the block 540 is a vertically extending opening 541which receives therethrough a metal tube 542 that extends downwardlyinto a larger cylindrical opening 543 formed in the lower portion of theblock 540 and downwardly beyond the lower end of the block 540 and intoa metal end piece 546. The end piece 546 is gen crally cylindrical inshape and has an outwardly extending flange 560 around the upper endthereof that is held against the lower end 544 of the block 540 by anannular metallic sleeve 547 which is threaded at 561 and threadcdlyengages the complementary threads on the exterior surface of the block540 at the lower end thereof. Extending inwardly from the lower edge ofthe sleeve 547 is a flange 562 which engages thc flange 560 on the endpiece 546 to clamp the end piece 546 to the lower end of the block 540.The lower end of the end piece 546 is generally closed by a wall 563having an aperture 548 generally centrally thereof and in longitudinalalignment with the tube 542. The lower end of the tube 542 has aconverging section thereon terminating in an orifice 549 that dischargesinto the end piece 546, and specifically into the reaction chamber 503formed thereby and in alignment with the aperture 548 in the end piece546.

Referring specifically to FIG. 14. it will be seen that the metallicsleeve 54'! has electrically connected thereto a conductor 516 and themetallic tube 542 has electrically connected thereto a conductor 517. Asuitable operating potential is applied between the conductors 516 and517 from a transformer 519, the transformer 519 specifically including aprimary winding 520 connected to a suitable source of operatingpotential at the connections 521 and 522, a typical source being a ll()volt A.C. 60 cycle Edison supply. The transformer 519 is provided with asecondary winding 518 having the end terminals thereof connectedrespectively to the conductors 516 and 517 and having the center thereofgrounded as illustrated. Also connected between the conductors 516 and517 is a capacitor 523 which has been illustrated as being of thevariable type. The power supply thus described is effective whenoperated to apply the necessary operating potentials between the tube542 which serves as one of the electrodes for the reactor 500 and thesleeve 547 which is directly connected electrically to the metallic endpiece 546 which serves as a second electrode for the reactor 500.

Mounted in the side of the block 540 is a pipe 550 having an openingtherein communicating at one end with the opening 543 within the block540 and at the other end communicating with one end of a conduit 551.The other end of the conduit 551 is connected to the outlet 552 of apump 553, the pump 553 having an inlet 554 connected to the atmosphere,whereby the pump 553 is operative to draw air from the atmosphere,compress the air and discharge a stream thereof through the conduit 551and the pipe 550 into the reaction chamber 503, the air stream thusproduced flowing around the exterior of the tube 542 and then downwardlyand outwardly through the aperture 548. The upper end of the tube 542 isconnected to the lower end of a conduit 555, the upper end of theconduit 555 communicating with a tank 556 containing liquid to beconveyed to the reactor 500, the flow of liquid from the tank 556 beingunder the urging of gravity and being regulated by means of a valve 557disposed in the conduit 555. By this construction, a liquid stream isestablished flowing through the tube 542 and outwardly from the lowerend thereof through the opening 549 and into the reaction chamber 503where the liquid stream is exposed to both the gas stream from the pipe550 and the spark discharge between the tube 542 and the end piece 546.The treated liquid stream together with the gas stream exits from theend piece 546 through 20 the aperture 548 in a combined stream as at 559and falls upon a suitable collector that is diagrammatically illustratedat 558 in FIG. 14.

The operating conditions for the reactor 500 are substantially the sameof those for the reactor 100 described above, whereby materials in thegas stream and liquid stream flowing through the reactor 500 aresubjected to the spark discharge taking place directly therein to causethe highly desirable physical and chemical reactions thereon.

Treatment 0 f starch The apparatus 20 of FIG. 1 incorporating thereactor 100 therein is particularly useful in the treatment of starch tomodify the physical and chemical characteristics thereof. The followingis a specific example of the treatment of corn starch utilizing theapparatus 20 of FIG. 1, the corn starch containing about 20% by weightamylose and the remainder being substantially amylopectin.

EXAMPLE 1 Pearl corn starch was slurried in cold water containingammonium chloride and hydrochloric acid. Sufficient hot water at 150 F.was added to the slurry to Warm it to a temperature of 118 F., carebeing exercised not to permit the temperature at any time to reach thegelatinization temperature of the starch. The starch slurry as preparedhad the following composition and characteristics:

Pearl corn starch21.6% by Weight Ammonium chloride4 grams per liter ofslurry Hydrochloric acid (37% by weight)To provide a pH Temperature-118P.

The resultant starch slurry was placed in the tank 92.

The power supply 30 was energized by closing the switch contacts 33-34after which the pump start switch 46 was closed to energize the motor tostart operation of the pump 94. The pump 94 was operated to deliver thestarch slurry to the reactor at a rate of 0.6 gallon per minute. An airline was connected to the conduit 88 and the air regulator 90 wasadjusted to permit air into the reactor 100 at a line pressure of 10psi. as indicated by the gauge 91. The reactor start switch 44 was thenclosed to energize the relay coil 51 to close the contacts associatedtherewith and to apply operating potential to the various transformersin the power supply 30. A spark discharge was immediately producedbetween the electrodes and in the reactor 100. After the reactor hadbeen running for several seconds, the tank 141 was placed in position toreceive the product issuing from the pipe at the bottom of the reactor100. The temperature of the stream entering the tank 141 was 122 F. Thepotential supplied to the primary windings of the step-up transformers80A, 80B and 80C as determined by the volt meters 64A, 64B and 64C was116 volts, the output from the secondary windings thereof was 12,000volts whereby the potential applied to the electrodes 120 and 130 wasapproximately 9,000 volts; the capacitance of the capacitors 85 was 0.05mierofarad and the current drawn as indicated by the ammeter 62A, 62Band 62C was approximately 20 amperes. The total reacted slurry in thetank 140 was then placed in an open container and air dried by blowingair thereover during a period of approximately 16 hours to provide thereacted starch product.

The reacted starch product differs in both its physical properties andits chemical properties from the pearl corn starch introduced into thereactor 100. For example, the apparent molecular weight as determined bythe viscosity of potassium hydroxide solutions thereof is materiallyreduced by passing the starch through the reactor 100 as describedabove. More specifically, the apparent molcctu lar weight of the pearlcorn starch before reaction is 21 approximately 1,148,500, whereas thereacted starch product has an apparent molecular weight of 294,620.

As utilized herein, the term apparent molecular weight refers to thevalue obtained by measuring the viscosity of potassium hydroxidesolutions containing the starch or the treated starch, as the case maybe. In making the determination of the apparent molecular weight, thestarch product is first Washed with a 96% ethyl alcohol solution toremove the ammonium chloride therefrom. 0.2 gram of the starch productwas carefully dissolved in 100 ml. of 1 molar aqueous potassiumhydroxide solution. The efilux time in seconds of the solution from anOstwalt-Fenske #50 or #100 viscometer as required Was determined. Arelative viscosity was then obtained using the formula:

"lrel s/to wherein, I, is the efllux time of the unknown sample, t isthe efilux time of the potassium hydroxide solution without any sampletherein, and 1 is the relative viscosity. Because of the non-idealbehavior of the starch solutions, the relative viscosity is dependentupon the concentration of the starch therein. A viscosity number atinfinite dilution is obtained by extrapolation of a plot of the relativeviscosity numbers versus concentration of the starch in the solutions ingrams per milliliter to yield the limiting viscosity number (or theintrinsic viscosity) in accordance with the following formula:

l ll LJ l1 7 ON] The limiting viscosity number is related to theapparent molecular weight (M) by the Staudinger equation:

where K and a are empirical constants for the starchsolvent system, thevalues for these constants in 1 molar potassium hydroxide being:

The above method is explained in further detail in Methods inCarbohydrate Chemistry, vol. 1V, P. L. Whistler, editor, Academic Press,Inc., New York, N.Y., 1964, pages 127 et seq., 179 and 180.

The reducing end groups present in the reacted starch product areconsiderably more numerous than those in the pearl corn starch that isthe starting ingredient, the pearl corn starch having end groupscorresponding to a ferricyanide reducing number of 0.5 as compared to avalue of 15.0 for the treated starch product. The ferricyanide reducingnumber referred to herein is the figure obtained utilizing the methoddeveloped by Thomas J. Schoch of Corn Products Company, Argo, Ill. andreported in detail in Methods in Carbohydrate Chemistry, vol. IV, R. L.Whistler, editor, Academic Press, Inc, New York, N.Y., 1964, pages 6467.Briefly, the method consists in adding alkaline ferricyanide solution toa starch sample dispersed in water and digesting the mixture at avigorous boil for 15 minutes. A zinc sulfate/ acetic acid solution isadded for color control after which a 20% by weight potassium iodinesolution in water is added. The iodine liberated by the reaction withthe reducing end groups is titrated with 0.05 N standard sodiumthiosulfate solution in Water. The milliliters of sodium thiosulfatesolution required is directly proportional to the reducing end groupcontent of the starch in accord ance with the following formula:

I for blank for sample thiosulfatc X It also has been determined thatthe apparent carboxyl content of the starch treated by the reactor issubstantially greater than that of the original pearl corn starch, theoriginal pearl corn starch value being sub stantially nil, and the valuefor the reacted corn starch of Example 1 above being 0.297. The methodutilized in determining the apparent percent carboxyl" is that set forthin the article entitled Determination of the Carboxyl Content ofOxidized Starches by M. F. Mattisson and K. A. Legendre, in AnalyticalChemistry, vol. 24, No. 12, December 1952, pages 1942-1944. This methodin brief consists of first washing the chloride from the starch sample.The starch sample is then slurried with water and cooked for about 6minutes to insure gelatinization. The hot, pasted starch is titratedwith 0.1 N sodium hydroxide to the phenolphthalein end point. Theapparent percent carboxyl" is attained from the following computation:

The amylose portion of the corn starch normally possesses a typicalhelical coil form which has a shape and characteristic such that wheniodine is added to a slurry of the starch, the iodine is entrapped inthe helical coil and imparts the characteristic blue color to thestarch. The addition of iodine to an aqueous slurry of the starchproduct from Example 1 causes the typical blue color to be formed in thestarch indicating that the helical coil form has been preserved. Theiodine test also indictates that the starch is more fluffy and moreflocculent and more dispersed than the untreated starch. Accordingly,the starch treatment in the reactor 100 although otherwise materiallychanging the physical and chemical characteristics of the starch, doesnot produce any significant destruction of the helical configuration ofthe amylose fraction thereof.

It will be understood that the various parameters and conditions setforth above with respect to Example 1 can be substantially changedwithout departing from the spirit and scope of the present invention.The concentration of starch in the slurry fed to the reactor 100 may beas little as 0.5% by weight and up to as much as 40% by weight, the onlylimitation being that the slurry must be capable of being transported bypumping through the reactor 100; the preferred concentration of starchin the slurry is about 20% by weight.

Although Example 1 illustrates the treatment of starch slurries havingan acid pH, an acid pH is not necessary, and satisfactory operation ofthe reactor 100 has been obtained utilizing starch slurries having a pHin the range from about 1.0 to about 9.0. The acid range is generallyfrom pH 1 to 6.5, the preferred pH lying in the range from about 1.5 toabout 3.0. In the basic pH range, the preferred pH is from about 7.5 toabout 9.0. Any acid is useful to create the desired acid pH that willreact with the starch in the general temperature range from about 70 F.to about F. substantially only to hydrolyze the star-ch by chainsission. An example of the preferred mineral acid is hydrochloric acid,and an example of the preferred organic acid is acetic acid. Any desiredbase may be utilized to create a basic pH, the preferred bases beingsodium hydroxide and ammonium hydroxide.

It further is desirable to buffer the starch slurry while it is in thereactor 100. When operating in the acid pH range, the preferred class ofbuffering agents are amines including ammonium ion, the lower aliphaticorganic amines such as triethanolamine and amino acids. As illustratedin Example 1 above, a suitable buffering agent in the acid range isammonium chloride, the concentration of the ammonium ion in the slurrybeing in the Weight; of sample on dry basis range from about 0.003 moleper liter to about 0.3 mole per liter, the preferred value asillustrated in Example 1 above being 0.075 mole per liter. Whenoperating in the basic pH range, the preferred buffering agents are theoxides of boron, such for example, as sodium tetraborate. A desirableconcentration of the borate in the slurry is in the range from about0.003 mole per liter to about 0.3 mole per liter, the preferredconcentration being 0.075 mole per liter. The amines and the borates arealso thought to accelerate the action of the reactor 100. In addition itis believed that the ammonium ions may tend to stabilize any freeradical reactions that are taking place in the reactor 100.

Starches can be treated in the temperature range from ambienttemperature up to about 140 F., care being taken that there is nogelatinization of the slurry. The preferred operating temperature rangeis from about 110 F. to about 120 F.

The flow rate of the starch slurry through the reactor 100 can also bevaried and may be as little as 0.05 gallon per minute and up to 1.5gallons per minute, the preferred flow rate being on the order of 0.6gallon per minute. The time that the slurry is subjected to the actionof the spark discharge is inversely related to the How rate, i.e., atthe slower flow rates there is a longer exposure time and at the higherflow rates there is a shorter exposure time. At the preferred flow rateof 0.6 gallon per minute, the exposure time is approximately 0.069second, whereas at the slightly lower llow rate of 0.45 gallon perminute, the exposure time is 0.091 second, and whereas at the higherflow rate of 1.5 gallons per minute, the exposure time is 0.027 second.

The air pressure supplied to the reactor 100 during the treatment of thestarch slurry can also be varied from that set forth in Example 1 above.A substantially lower pressure on the order of 5 p.s.i. can be used orsubstantially higher pressures on the order of 50 psi. or higher may beused. As has been pointed out heretofore the efiiciency of the transferof energy to the spark discharge is increased at the higher airpressures, whereby an air pressure on the order of p.s.i. as indicatedby the gauge 91 is preferred.

The operating potential applied between the electrodes 120 and 130 maybe from about 4,500 volts to about 20,000 volts or higher, the preferredvalue being on the order of about 9,000 volts. In passing it is pointedout that despite the applied potential, the actual potential at which adischarge is obtained is determined fundamentally by the geometry of thereactor 100 and the characteristics, concentrations and conditions ofthe reactants flowing therethrough.

A wide variety of types of starch can be treated in the apparatus 20 ofFIG. 1. In addition to the corn starch illustrated, starches from otherseeds, roots and tubers can also be treated. All starches arefundamentally composed of a mixture of two polymers, amylose andamylopectin. Starches containing substantially no amylose, such as waxymaize, can be successfully treated in the apparatus 20 of FIG. 1.Furthermore, starches having higher appropriations of amylose may alsobe successfully treated, i.e., starches having more than 20% amylosecontent. For certain purposes, it is preferred that the starch slurrypassing through the reactor 100 contain at least about 5% amylose byweight as will be ex plained more fully hereinafter.

Instead of only passing the starch slurry once through the reactor 100,it will readily be understood that a slurry can be repeatedly recycledthrough the reactor 100 by providing a suitable interconnection betweenthe tanks 92 and 141. The chemical and physical properties of thestarches are materially altered after multiple passes through thereactor 100, and there are illustrated in FIGS. 16, 17 and 18 of thedrawings, changes in the various physical and chemical properties of thestarches as a result of multiple passes through the reactor 100.

Referring first to FIG. 16, there is plotted thereon the relationshipbetween the apparent molecular weight and the number of passes that thestarch slurry makes through the reactor 100. The curve 160 plots therelationship between the apparent molecular weight and the passesthrough the reactor for corn starch wherein the process is carried outin accordance with Example 1 above. It will be seen that the apparentmolecular weight generally decreases with additional passes of thestarch slurry through the reactor 100, the apparent molecular weight for1 pass being approximately 295,000, the apparent molecular Weight for 2passes being approximately 220,000, the apparent molecular weight for 3passes being approximately 216,000, the apparent molecular weight for 10passes being approximately 151,000, and the apparent molecular weightfor 15 passes being approximately 39,000. There also is plotted in FIG.16 a curve 162 showing the effect of passing the same starch slurry ofExample 1 through the reactor 100 but without applying the potential tothe electrodes and so that no spark discharge occurs therein. It will beseen that the apparent molecular weight still decreases but not sorapidly as when the spark discharge is present, the molecular weight for1 pass without spark discharge being approximately 386,000, for 2 passesbeing approximately 276,000, for 3 passes being approximately 256,- 000,for 10 passes being approximately 234,000 and for 15 passes beingapproximately 187,000. There further is plotted in P16. 16 the curve 164which illustrates the effect of treating waxy maize starch in accordancewith Example 1 above, it being pointed out that waxy maize starchcontains substantially 100% amylopectin. Immediately upon being placedin the slurry for a period of time corresponding to 1 pass, the apparentmolecular weight drops from the untreated value of 466,000 to a value of18,000, this value being plotted as the pass value in FIG. 16 on graph164. For 1 pass through the reactor 100 with the spark dischargepresent, the apparent molecular weight actually rises to about 24,000,and for 15 passes through the reactor 100 with the spark dischargepresent, the apparent molecular weight rises to approximately 49,000.Accordingly, it will be seen that in using the reactor 100 to treat astarch comprising esscntially 100% amylopectin, the apparent molecularweight substantially increases, whereby it is believed that theamylopectin fraction of the corn starch in the curve is likewise beingacted upon to increase the apparent molecular weight, and accordingly,the amylose faction is believed to be acted upon fundamentally todecrease the apparent molecular weight thereof.

There is illustrated in FIG. 17 of the drawings a plot of theferricyanide reducing number against the number of passes of the starchslurry through the reactor 1.00. There is plotted on the curve theferricyanide reducing number for corn starch reacted in accordance withExample 1 above, and it will be seen that the terricyanide reducingnumber steadily increases with additional passes through the reactor100. More particularly, the ferricyanide reducing number increases froma value of 15.0 for 1 pass to a value of 15.25 for 2 passes to a valueof 16.15 for 10 passes and to a value of 19.0 for 15 passes. There isplotted on the curve 172 the ferricyanide reducing numbers obtained bycarrying out the process of Example 1 but without applying the sparkdischarge to the starch slurry in the reactor 100. It will be seen thatthe ferricyanide reducing number generally decreases with additionalpasses of the starch slurry through the reactor 100, the value being12.63 for 1 pass, 12.12 for 2 passes, 11.37 for 3 passes, 10.25 for 10passes, and 9.87 for 15 passes. There further is plotted in FIG. 17 thecurve 174 plotting ferricyanide reducing numbers for waxy maize starchtreated in accordance with Example 1 above. Treatment with ammoniacalacid solution without passage through lhe reactor provides aferricyanide reducing

46. THE METHOD OF MAKING PAPER COMPRISING THE STEPS OF PROVIDING A STOCKINCLUDING PAPER-MAKING FIBERS AND A STARCH DERIVATIVE CHARACTERIZED BYAN APPARENT MOLECULAR WEIGHT IN THE RANGE FROM ABOUT 35,000 TO ABOUT350,000 AND A FERRICYANIDE REDUCING VALUE IN THE RANGE FROM ABOUT 14 TOABOUT 20, FORMING A WET SHEET FROM THE STOCK, AND DRYING THE WET SHEETTO PROVIDE A FINISHED PAPER FORMED OF THE PAPERMAKING FIBERS ANDCARRYING THE STARCH DERIVATIVE AS A SIZING THEREON.